Bolt.



ENT FEE.

ETHAN I. DODDS, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO FLANNERY BOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA.

BOLT.

To all whom it may concern:

Be it known that I, ETI-IAN I. DODDS, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Bolts; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in bolts designed more particularly for railroad track construction and is a division of application No. 13,884 filed by me March 12, 1915.

The object of the invention is to provide a bolt capable of slight elongation or spring action longitudinally, and which will resume its normal length after the stress has been removed, thus preventing the metal in the bolt from becoming permanently set, and removing, to a large extent the tendency of the nuts to work loose, and it consists in the details of construction as will be more fully explained and. pointed out in the claims.

In the accompanying drawings, Figure 1 is a view in elevation of a bolt embodying my invention; Fig. 2 is an end elevation of the same; Fig. 3 is a view in longitudinal section of Fig. 1; Fig. 4 is a View in transverse section and Fig. 5 is a view of the bolt showing the slot closed and the shank twisted and threaded.

In the manufacture of the bolt a round bar of steel is headed in the usual manner, and while it is hot from the original heating or reheating, it is slotted as at 1, comparatively thin walls or partitions 4 being left at both ends and at point or points intermediate the ends, the said walls or partition operating to hold the two side members of the bolt in proper position and at the same time permit them to yield or give under the stresses to which the two members of the bolt are subjected. The slot 1 passes through the bolt, and the integral partitions 4 at the ends and intermediate point or points, ex-

.Specification of Letters Patent. Patgntgd Nay. 21, 1916,

. Original application filed March 12, 1915, Serial No. 13,884. Divided and this application filed May 22,

I Serial No.-29,849.

tend the full diameter of the bolt, and operate to retain the two parts of the bolt in proper relative positions.

The slots may be formed by cutting, punching, or in the process of rolling the blank, but if out or punched I prefer to do it with a tool that simply expands the blank without removing any of the metal. The slots thus formed are closed between dies or other tools, without welding the walls of the slots and this blank or bolt thus formed is twisted about a quarter turn so that the closed slots are in the form of spirals each extending approximately 90 around the bolt shank, after which the threads 5 are formed. These threads may be hot or cold rolled, or they may be cut, but in either event they are formed after the bolt shank has been twisted. During the process of manufacture, and before or after the threads have been out, I prefer to temper the bolts in oil so as to increase their hardness without affecting their elasticity.

A steel bolt slotted and twisted as described is capable of slight elongation which permits it to yield or give under the pounding of the wheels on the rails at the joints, and immediaely goes back to normal length as soon as the strains are relieved. This prevents permanent elongation of the bolt, and maintains the nut at all times under a pres sure sufficient to prevent it from turning, as it does on ordinary bolts after usage suflicient to cause a slight elongation of the bolt. By constructing the bolt so that it will give under stress and go back to normal length, the nut will always be under the original pressure to which it was subjected when applied to the bolt.

\Vhile I have designed the bolt for rail road track construction, it may be used for other purposes where an extensible or resilient bolt is desirable.

lVhile the exact sequence of steps may not be essential, I prefer to subject the bar or blank to a mellow heat and then shape it in dies or other suitable tools to produce an enlarged head. The shank of the bolt is then pierced or slotted, after which the slots tending through the shank lengthwise the latter, the said slots being closed at their outer ends and separated at their adjacent ends by a partition, the said shank being twisted and threaded. i

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

ETHAN I. DODDS.

or iinpiercements are closed, the shank twisted and the bolt smoothed, straightened and threaded.

Having fully described my invention wha 5 I claim as new and desire to secure by Letters-Patent, is

1. A bolt having a plurality of slots extending through the shank lengthwise the latter, the slots being closed at their outer 10 ends and separated at their adjacent ends by a partition.

2. A bolt having a plurality of slots ex- Witnesses:

F. H. ALLISON, EDWIN S. RYCE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner (at Patents, Washington, D. C. 

